switch it on and use the left zero knob to zero it,the the right knob flick it to rx1000,touch two probes together until the meter needle jumps,to test caps just insert the probes either way around into each end of the cap,if its good the needle will swing to around number 5,times 1000 = 5000,with the right hand knob set to rx100 the needle should jump to 50 on the scale,times 100=5000.